Ejector refrigeration system
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Solution Overview
Problem
Ejector refrigeration systems using carbon dioxide as a fluid medium face inefficiencies and malfunctions when external ambient temperatures are low due to insufficient pressure lift, leading to reduced refrigeration energy efficiency and complex structures with high costs.
Innovation Solution
The system incorporates a phase adjustment mechanism to adjust the fluid working medium entering the ejector into a gas-liquid two-phase state, utilizing components like a differential pressure sensor, expansion valve, and bypass pipeline to optimize the gas-liquid ratio, ensuring sufficient pressure lift and uninterrupted operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the ejector refrigeration system operates in low external ambient temperature conditions, then the fluid pressure at the outlet of the first heat exchanger becomes excessively low, but the ejector cannot provide sufficient pressure lift and the working medium pressure at the ejector outlet cannot be raised to the specified pressure
Solution Approach 1:
The patent adjusts the phase state parameter of the fluid working medium entering the ejector by introducing a phase adjustment mechanism. This mechanism modifies the gas-liquid ratio of the working medium to optimize the ejector's pressure lift capability under low ambient temperature conditions, enabling the system to maintain adequate outlet pressure despite the excessively low inlet pressure.
Solution Approach 2:
The patent replaces complex mechanical pressure boosting systems (such as booster pumps or bypass valves) with a phase adjustment mechanism that utilizes phase change properties of the working medium. This substitution simplifies the system structure while effectively addressing the pressure lift insufficiency problem in low temperature environments.
2Reliability
If a booster pump or bypass branches are added to ensure sufficient pressure lift, then the normal operation of the refrigeration system is ensured, but the structure becomes complex and the cost increases
Solution Approach 1:
The patent extracts and eliminates the need for complex pressure boosting equipment (booster pumps, bypass branches, solenoid valves, pressure regulating valves) by introducing a phase adjustment mechanism. This mechanism directly addresses the pressure lift problem at its source by modifying the working medium's phase state, thereby simplifying the overall system structure while maintaining reliability.
Solution Approach 2:
The phase adjustment mechanism enables the ejector system to self-regulate and maintain adequate pressure lift by utilizing the inherent phase change properties of the working medium. This self-service capability eliminates the need for external mechanical assistance systems, reducing structural complexity while ensuring continuous normal operation.
3Reliability
If bypass branches with multiple solenoid valves and pressure regulating valves are added, then the refrigeration system can operate normally, but the refrigeration energy efficiency is reduced
Solution Approach 1:
The phase adjustment mechanism optimizes the energy efficiency by precisely controlling the phase state and gas-liquid ratio of the working medium entering the ejector. This parameter optimization ensures that the ejector operates at peak efficiency under low ambient temperature conditions, minimizing energy losses associated with bypass operations and valve actuations while maintaining system reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the pressure lift of the ejector, maintains system reliability, reduces energy consumption, and simplifies the structure, thereby improving operational efficiency and cost-effectiveness.
Implementation Method 1
the ejector 300 cannot provide sufficient pressure lift, and a working medium pressure at an outlet of the ejector 300 cannot be raised to a specified pressure
Implementation Method 2
a phase adjustment mechanism configured to adjust a phase state of the fluid working medium entering the primary flow inlet of the ejector
Implementation Method 3
the phase adjustment mechanism is a mechanism for controlling an opening degree of the expansion valve
Implementation Method 4
a differential pressure sensor configured to measure a differential pressure between the secondary flow inlet of the ejector and the ejector outlet
Implementation Method 5
a gas-liquid separator including an inlet connected to the ejector outlet, a gas outlet connected to the suction port of the compressor, and a liquid outlet
Data Source
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AI summary
An ejector refrigeration system includes: a compressor (1) having a suction port (11) and a discharge port (21); a first heat exchanger (2) connected to the discharge port of the compressor to receive a fluid working medium flowing out from the discharge port of the compressor; and an ejector (3) including a primary flow inlet (31) connected to the first heat exchanger to receive a fluid working medium from the first heat exchanger, a secondary flow inlet (32), an ejector outlet (33) connected to the suction port of the compressor to return a fluid working medium entering the ejector to the suction port of the compressor, and a phase adjustment mechanism configured to adjust a phase state of the fluid working medium entering the primary flow inlet of the ejector or adjust a gas-liquid ratio of the fluid working medium at the primary flow inlet.